Improvement in photographic printing-frames



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Patenfed Oct. 24,1871.

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UNITED STATES PATENT OFFICE JOHN GEORGE COEFTN, OF PORTSMOUTH, OHIO, ASSIGNOE TO SENSITIZED PAPER COMPANY, OE SAME PLACE.

IMPROVEMENT IN PHOTOGRAPHIC PRINTING-FRAMES.

Specification forming part of Letters Patent No. 120,245, dated October 24, 1871.

ToV all whom it may concern:

Be it known that I, J oEN GEORGE GoFFIN, of the city of Portsmouth, county oi' Scioto and State of Ohio, have invented a combined photo graphic Printing and Filming-Frame, oi' which the following is a specication:

The printing-board now in use consists of two flat boards lapped together at an angle of about forty-iive degrees, and held together with hinges, making a smooth flat surface, on which the nega tive is put, so that one hali' occupies each part ofthe board. A pad orcloth is placed on the board, sometimes impregnated with the fumes and sometimes with the dry salts of ammonia, but usually with neither, over which the sensitive paper is laid, and the negative over the paper. The whole is then exposed to the sun for printing. If the pads are impregnated with neither the fumes nor salts of ammonia, the sensitive paper is subjected to the fumes of ammonia in a box constructed for the purpose. My improvement consists in a combination of fuiningbox and printing-board in one, differing essentially from the ordinary mode in this particulareither in fumed pads or finned paper the ammonia gas quickly escapes, thus leaving the paper inscn sible to its eects when most needed. In my combination a constant supply of ammonia is supplied to the paper from the ammonia-chamber underneath the paper, which can only escape by coming in contact with sensitive paper, thus saving the transfer, of the paper from the fumingbox to the printing-board, and the ammonia in making the transfer.

Figure l is a side elevation oi' my printingframe. Fig. 2 is a section of bottom and side.

A A and B B, wooden-traine, divided into two parts at O O and held together by hinges D D; F, ammonia-chamber in center of frame 5 G, wires stretched ironi A to A even with the top of frame; J J, wedges or keys, to spread the frame B B and A, tightening the wires G 5 C, porous cloth spread over the wires G; E, metal springs, for holding the paper and negative on the cloth C; H, piece of wood attached to the frame A, Fig. l; I, pin projecting from A, Fig. 2, upon which rests H, preventing the frame from bending backward. In 2 A, side; B, end of frame; N, leather or covering over bottom of chamber; K, button to hold the frame level, L, wooden slide, in two parts, which enters the chamber through the end B; M, cloth covering slide, which is saturated with ammonia.

I claim as my invention- The hollow chamber, covered with a perforated top, under the negative. l

JNO. G. GOFFIN. XYitn esses:

XVILLIAM B. YVALLAM, MosEs E. MILLER. 

